1. Field of the Invention
The invention broadly pertains to electrical connectors for wire or cable conductors. More specifically, the invention relates to a compression-type electrical connector for connecting a first conductor to a second conductor in an electrical power distribution system. The invention finds particular application in establishing a tap connection to provide a branch current from a continuous run main power cable. An electrical connector of the aforesaid type is typically adapted to receive a tap conductor, to engage a continuous run conductor, and to be compressed by means of a crimping tool to achieve the desired connection.
In order that the electrical connector may efficiently and safely be installed on the continuous run conductor, it is desirable that it possess a configuration which allows it to be easily hooked onto the run conductor. Additionally, because the run and tap conductors may be fabricated of different metals, it is desirable that the connector isolate the respective conductors from each other so as to prevent rapid galvanic corrosion. Distinctions in the conductors which may be utilized for various applications make it further desirable that the connector accommodate a range of sizes for the respective conductors. Moreover, a further desirable feature for this type of electrical connector is that the conductor members be securely frictionally held in the cavities provided to retain them. Finally, limited access to the run conductor, which is a frequent characteristic of installation conditions, makes it desirable that the electrical connector be adapted for insertion in the compression tool with one of the conductors already installed and secured therein, enabling the connector to engage the other conductor and to be compressed immediately. It is highly advantageous, therefore, that the electrical connector present positive means for securing one of the conductors during the installation process. Even further adaptability to diverse installation conditions would be provided by the securing means being capable of selectively enclosing one or the other of the conductors during installation.
The present invention accomplishes the foregoing objectives by providing an electrical connector which is specifically configured to accept a wide range of conductor sizes, which provides conductor receiving cavities characterized by frictional gripping means capable of deforming to vary the size of the cavities, which isolates the conductors from each other to prevent galvanic corrosion, which provides a manually deformable member for positively retaining a selective one of the conductors prior to compression, and prior or subsequent to insertion in a compression tool, and which is adapted to be easily and quickly applied to the other of the conductors for immediate compression.
2. Description of the Prior Art
U.S. Pat. No. 3,053,930, which issued to Mallanik et al on Sept. 22, 1962, and which is commonly owned by the assignee of the subject invention, discloses an electrical connector possessing several features similar to those of the present invention. Mallanik et al teaches an electrical connector comprising a generally C-shaped body. A central web is disposed within the interior of the body so as to form an E-shaped configuration which defines an upper and a lower cavity. A tap conductor is intended to be inserted into either of the cavities, whereupon the central web is manually bent down by the installer on top of the tap conductor to lock it in position. The connector, with the tap conductor secured therein, may then be inserted into a compression tool, hooked onto a run conductor, whereby the run conductor is received in the other remaining cavity, and then compressed.
Mallanik et al teaches the central web as being formed separate from the body of the conductor and either staked within a groove in the body (FIG. 1), or attached to the body by means of a ball and socket joint (FIG. 4). Both of the latter embodiments, comprising as they do separable body and web members, permit the web members to be formed longer than the body, so that the central web projects from both ends of the body as illustrated in FIG. 1. It is these projecting ends of the web member which are in practice manually grasped by and pushed down upon by the installer to bend the central web down on top of the conductor to be secured in the connector.
Although Mallinick et al depicts the central web as being hingedly connected to the body of the connector in FIGS. 2 and 3, the latter embodiments are unitary members, being cut from extruded bars. As such, the ends of the central webs would not project beyond the ends of the body member, but would in fact be the same length as the body member. Furthermore, the central web is located in the central space defined by the upper and lower arms of the body member and, as such, does not project beyond the arms of the body member. Consequently, the integral electrical connector having a hinged central web shown by Mallinick et al is impractical and, indeed, virtually impossible to utilize in its intended manner for the reason that the installer is unable to bend the central web down on top of the tap conductor. This is so because the installer has no way of grasping the central web, other than through the relatively restricted opening formed between the upper and lower arms of the body member, which opening, particularly for a lineman installer with gloves on, is too small for feasible installation.
The instant invention provides all of the functional benefits which are associated with the connectors of Mallinick et al while overcoming the deficiencies associated therewith.
It is also generally known in the prior art to provide an electrical connector having a body of C-shaped configuration. U.S. Pat. No. 4,087,889 to Ohba et al, U.S. Pat. No. 1,631,719 to Chandler. U.S. Pat. No. 2,930,113 to Greco and U.S. Pat. No. 3,387,080 to Dibble et al generally disclose C-shaped connecting devices wherein one or more conductors are intended to be disposed within the open cavity defined by the C-shaped connector with the connector being subsequently compressed.
The prior art further discloses electrical connectors for connecting tap and run conductors wherein the conductors are electrically and mechanically retained within a C-shaped body member by means of toggle blocks. For example, U.S. Pat. No. 4,734,062 to Goto, which issued on Mar. 29, 1988, shows an electrical connector comprising a C-shaped body member which defines channels dimensioned to receive a range of sizes of conductors. Once the conductors which are to be connected are placed in the body member, hingedly connected toggle blocks are positioned in the body member. The toggle blocks are intended to be forced into the body member, thereby compressing the conductors in their respective channels and providing an electrical interconnection between same. A similar device is disclosed in U.S. Pat. No. 4,723,921, which issued to Pooley on Feb. 9, 1988.
A further variety of tap and run electrical connectors known in the prior art are of the H-shaped configuration. U.S. Pat. No. 3,546,366 to Toedtman, which issued on Dec. 8, 1970, for instance, shows a compressible electrical connector having an H-shaped body wherein a pair of arms and an intervening partition define conductor receiving recesses. Each of the recesses is provided with ribs which deform under pressure to accommodate the conductor size and configuration. A tab member is attached to each end of one of the arms for pivotable movement by means of a compression tool into position over a respective conductor disposed in the associated recess. Portions of the tab members mate with the opposite arm when the tab is in the compressed state.
Similarly, Levinsky. U.S. Pat. No. 3,354,517 of Nov. 28, 1967, discloses a compressible connector of H-shape configuration formed by a pair of side walls and an intermediate connecting web portion which together define major cable accommodating recesses. A re-entrant recess is provided in each of the side walls in the web area for receiving endwise wires and conductors.
U.S. Pat. No. 3,236,938 to Toedtman, bearing an issue date of Feb. 22, 1966, teaches an H-shaped compressible connector wherein one of the arms of the connector body is provided at its ends with a bendable tab. The tabs are adapted to be bent inwardly, as by means of the fingers, toward the other arm of the connector body.
U.S. Pat. No. 3,235,654, which issued to Eldridoe, Jr. on Feb. 15, 1966, similarly discloses an H-shaped connector. As illustrated therein, an end of one arm of the body member is provided with a bendable tab (FIG. 1), and, additionally, the opposite end of the other arm of the body member may be provided with such a tab (FIG. 3).
Finally, Toedtman, U.S. Pat. No. 3,156,764 of Nov. 10, 1964, is directed to an H-shaped compressible electrical connector characterized by bendable tabs at the ends of one of the arms of the body, and by deformable ribs which project from the body into the conductor receiving recesses.
The prior art fails to teach or suggest a compressible electrical connector including an integral E-shaped body member provided with a central movable retaining member which projects beyond and is accessible from outside of the cavity defined by the body member, and which may be selectively bent over a desired one of plural conductor receiving cavities to retain and isolate a conductor located therein.